Tuenchit Khamapirad

Laser optoacoustic imaging system for detection of breast cancer

We designed, fabricated and tested the laser optoacoustic imaging system for breast cancer detection (LOIS-64), which fuses optical and acoustic imaging techniques in one modality by utilizing pulsed optical illumination and ultrawide-band ultrasonic detection of resulting optoacoustic (OA) signals. The system was designed to image a single breast slice in craniocaudal or mediolateral projection with an arc-shaped array of 64 ultrawide-band acoustic transducers. The system resolution on breast phantoms was at least 0.5 mm. The single-channel sensitivity of 1.66 mVPa was estimated to be sufficient for single-pulse imaging of 6 to 11 mm tumors through the whole imaging slice of the breast. The implemented signal processing using the wavelet transform allowed significant reduction of the low-frequency (LF) acoustic noise, allowed localization of the optoacoustic signals from tumors, and enhanced the contrast and sharpened the boundaries of the optoacoustic images of the tumors. During the preliminary clinical studies on 27 patients, the LOIS-64 was able to visualize 18 out of 20 malignant lesions suspected from mammography and ultrasound images and confirmed by the biopsy performed after the optoacoustic tomography (OAT) procedure.

Optoacoustic imaging of blood for visualization and diagnostics of breast cancer

Aggressive malignant tumors may be diagnosed based on relative concentration of oxyhemoglobin and deoxyhemoglobin in the tumor microvasculature. Optoacoustic images of breast cancer and prostate cancer may be acquired at two laser wavelengths matching maximum of oxyhemoglobin (1064-nm, Nd:YAG laser) and deoxyhemoglobin (760-nm, Alexandrite laser). Two optoacoustic systems operating in forward and backward mode respectively for breast cancer and prostate cancer detection, employing arrays of ultravide-band piezoelectric transducers and multichannel electronics was described. After systems testing and calibration in phantoms, initial experiments were performed on patients with suspicious tumors. Quantitative analysis of two-color optoacoustic images was correlated with biopsy and histology. Possibility for tumor differentiation was demonstrated.

Detection and noninvasive diagnostics of breast cancer with two-color laser optoacoustic imaging system

We have designed, fabricated and tested a new laser optoacoustic imaging system (LOIS-64/16) for quantitative optoacoustic tomography of breast cancer. The system was designed to create a single slice of an optoacoustic image of the breast with 64 ultrawide band acoustic transducers. Other 16 transducers on the back of the acoustic probe were used to reconstruct the light distribution inside the breast. The system resolution was at least 0.5 mm for high-aspect-ratio objects. Maximum system sensitivity was 4.8 mV/Pa and the RMS noise of 3.1 mV, which allowed imaging of small (less than 1 cm) tumors at depths over 3 cm. The directivity of the optoacoustic transducers used in LOIS-64/16 assured that the signal detection was better than 70% of the maximum for about 75% of the imaging slice and reduced quickly for signals coming from out of the imaging slice. Implemented signal processing allowed significant reduction of the low-frequency acoustic noise and localizing the small OA signals. The system was able to differentiate phantoms mimicking tumors and malformations visualized in clinics based on the contrast and morphology of their images obtained at 1064 nm and 757 nm.

Diagnostic imaging of breast cancer with LOIS: clinical feasibility

Optoacoustic imaging is a promising new tool for the detection and diagnosis of breast cancer. It is progressing from research study to clinical evaluation. We have now built a complete laser optoacoustic imaging system (LOISTM) consisting of a laser illumination system, a 32-element ultrasonic detector probe, signal amplifiers, and a computer with software for image generation. This report describes initial tests to explore the clinical viability of the system. Our results show that the system has sufficient sensitivity to reveal cancerous tumors already identified with X-ray and/or ultrasound imaging, that it has the resolution to show faithfully the size and shape of those tumors, that comparison of images taken at 755 and 1064 nm is indicative of whether or not a suspicious lesion is cancerous, and that the depth of sensitivity of the system is sufficient to detect tumors throughout an average-sized breast.

Comparison of breast tissue measurements using magnetic resonance imaging, digital mammography and a mathematical algorithm

Women with mostly mammographically dense fibroglandular tissue (breast density, BD) have a four- to six-fold increased risk for breast cancer compared to women with little BD. BD is most frequently estimated from two-dimensional (2D) views of mammograms by a histogram segmentation approach (HSM) and more recently by a mathematical algorithm consisting of mammographic imaging parameters (MATH). Two non-invasive clinical magnetic resonance imaging (MRI) protocols: 3D gradient-echo (3DGRE) and short tau inversion recovery (STIR) were modified for 3D volumetric reconstruction of the breast for measuring fatty and fibroglandular tissue volumes by a Gaussian-distribution curve-fitting algorithm. Replicate breast exams (N = 2 to 7 replicates in six women) by 3DGRE and STIR were highly reproducible for all tissue-volume estimates (coefficients of variation <5%). Reliability studies compared measurements from four methods, 3DGRE, STIR, HSM, and MATH (N = 95 women) by linear regression and intra-class correlation (ICC) analyses. Rsqr, regression slopes, and ICC, respectively, were (1) 0.76-0.86, 0.8-1.1, and 0.87-0.92 for %-gland tissue, (2) 0.72-0.82, 0.64-0.96, and 0.77-0.91, for glandular volume, (3) 0.87-0.98, 0.94-1.07, and 0.89-0.99, for fat volume, and (4) 0.89-0.98, 0.94-1.00, and 0.89-0.98, for total breast volume. For all values estimated, the correlation was stronger for comparisons between the two MRI than between each MRI versus mammography, and between each MRI versus MATH data than between each MRI versus HSM data. All ICC values were >0.75 indicating that all four methods were reliable for measuring BD and that the mathematical algorithm and the two complimentary non-invasive MRI protocols could objectively and reliably estimate different types of breast tissues.

Computing mammographic density from a multiple regression model constructed with image-acquisition parameters from a full-field digital mammographic unit.

Breast density (the percentage of fibroglandular tissue in the breast) has been suggested to be a useful surrogate marker for breast cancer risk. It is conventionally measured using screen-film mammographic images by a labor-intensive histogram segmentation method (HSM). We have adapted and modified the HSM for measuring breast density from raw digital mammograms acquired by full-field digital mammography. Multiple regression model analyses showed that many of the instrument parameters for acquiring the screening mammograms (e.g. breast compression thickness, radiological thickness, radiation dose, compression force, etc) and image pixel intensity statistics of the imaged breasts were strong predictors of the observed threshold values (model R(2) = 0.93) and %-density (R(2) = 0.84). The intra-class correlation coefficient of the %-density for duplicate images was estimated to be 0.80, using the regression model-derived threshold values, and 0.94 if estimated directly from the parameter estimates of the %-density prediction regression model. Therefore, with additional research, these mathematical models could be used to compute breast density objectively, automatically bypassing the HSM step, and could greatly facilitate breast cancer research studies.

Bilateral Extensive Ductitis Obliterans Manifested by Bloody Nipple Discharge in a Patient with Long-Term Diabetes Mellitus

Abstract:  Ductitis obliterans or mastitis obliterans is a rare late manifestation of mammary ductal ectasia. We describe a long‐term diabetic patient who presented with bilateral bloody nipple discharge and poorly defined nodularities around the nipple of both breasts. The ductography showed multiple segments of irregular ductal narrowing and intraluminal filling defects in both breasts. The bilateral resection of the sub‐areolar portion of the breast showed exuberant fibrous obliteration of the large‐ and medium‐sized ducts by granulation tissue associated with few histiocytes. Ductal dilatation and intraductal accumulation of histiocytes was also present. This represents a late and florid form of mammary ductal ectasia. Differential diagnostic considerations including fibrocystic changes, diabetic sclerosing lymphocytic lobulitis, idiopathic granulomatous lobular mastitis, and periductal mastitis (Zuska disease) are discussed. Accurate diagnosis can help avoid or limit radical surgeries in this group of patients.

Similarity of Fibroglandular Breast Tissue Content Measured from Magnetic Resonance and Mammographic Images and by a Mathematical Algorithm

Women with high breast density (BD) have a 4- to 6-fold greater risk for breast cancer than women with low BD. We found that BD can be easily computed from a mathematical algorithm using routine mammographic imaging data or by a curve-fitting algorithm using fat and nonfat suppression magnetic resonance imaging (MRI) data. These BD measures in a strictly defined group of premenopausal women providing both mammographic and breast MRI images were predicted as well by the same set of strong predictor variables as were measures from a published laborious histogram segmentation method and a full field digital mammographic unit in multivariate regression models. We also found that the number of completed pregnancies, C-reactive protein, aspartate aminotransferase, and progesterone were more strongly associated with amounts of glandular tissue than adipose tissue, while fat body mass, alanine aminotransferase, and insulin like growth factor-II appear to be more associated with the amount of breast adipose tissue. Our results show that methods of breast imaging and modalities for estimating the amount of glandular tissue have no effects on the strength of these predictors of BD. Thus, the more convenient mathematical algorithm and the safer MRI protocols may facilitate prospective measurements of BD.

Diagnostic imaging of breast cancer microvasculature with optoacoustic tomography

We report first clinical results of diagnostic imaging of breast cancer patients with optoacoustic tomography (OAT). OAT combines the most compelling features of light and sound for medical imaging: high tissue contrast and excellent resolution. Aggressive malignant tumors were diagnosed based on relative concentration of oxy- and deoxy-hemoglobin in the tumor microvasculature. Optoacoustic images of breast cancer were acquired at two laser wavelengths matching maximum of oxyhemoglobin (1064-nm) and deoxyhemoglobin (760-nm). Quantitative analysis of two-color optoacoustic images was correlated with immunohistology of biopsy specimens. The possibility for noninvasive differentiation of malignant carcinoma from benign fibroadenoma was demonstrated.

Atypical papillary lesions after core needle biopsy and subsequent breast carcinoma

Abstract Background: Papillary lesions of the breast cause diagnostic problem because papillary structures are found in benign and malignant processes. Core needle biopsy is important to make an initial diagnosis, but it still has potential pitfalls. Comparison between core needle biopsy and excisional biopsy can predict the possibility of malignant change in atypical papillary lesions. Objective: Evaluate the concordance between core needle biopsy and excisional results in atypical papillary lesions of the breast. Materials and methods: The pathology database of University of Texas Medical Branch at Galveston, USA was searched for patients with atypical papillary lesions at core needle biopsy who subsequently underwent surgical excision. Pathology reports from the excisional biopsies was also examined to assign each case to one of three categories, downgrade to benign papilloma, no change (remained atypical papillary lesion), and upgrade to carcinoma. The mammograms and ultrasounds were reviewed for each case. They characterized the lesions according to multiple imaging criteria. Results: Twenty-four patients with atypical papillomas at core biopsy subsequently underwent surgical excision. The lesions were downgraded to benign papilloma in 25%, remained atypical papillary lesion in 33%, and upgraded to carcinoma in 42%. On mammographic presentations (n = 23), masses were in 61%, architectural distortion in 4.3%, mass with calcifications in 9%, mass with architectural distortion and calcifications in 4.3%, calcifications alone in 17.4%, and architectural distortion and calcifications in 4.3%. On ultrasound findings (n = 21), solid masses were in 90%, intracystic masses in 10%, peripheral in locations in 81%, and subareolar in location in 19%. Conclusion: Due to the high upgrade rate of atypical papillary lesions to carcinoma (42%), excision of all atypical papillary lesions with wide excision margin is recommended for cases with pathologic diagnosis of atypical papillary lesion on core-needle biopsy.